The ever-increasing demand for smaller sized mobile devices, such as cell phones, digital cameras, etc. has correspondingly triggered a growing need for smaller sized photography modules comprising elements such as an optical imaging lens, a module housing unit, and an image sensor, etc., contained therein. Size reductions may be contributed from various aspects of the mobile devices, which include not only the charge coupled device (CCD) and the complementary metal-oxide semiconductor (CMOS), but also the optical imaging lens mounted therein. When reducing the size of the optical imaging lens, however, achieving good optical characteristics becomes a challenging problem.
The length of conventional optical imaging lenses comprising four lens elements can be limited in a certain range; however, as the more and more demands in the market for high-end products, high-standard optical imaging lenses, such as the optical imaging lenses comprising six lens elements, which show great quality with more pixels are required.
U.S. Pat. No. 8,355,215 disclosed an optical imaging lens constructed with an optical imaging lens having six lens elements. The length of the optical imaging lens of patent '215, which, from the object-side surface of the first lens element to the image plane, is about 2 cm. Although the image quality of the optical imaging lens is acceptable, the volume of the optical imaging lens is too large to be suitable for small sized electronic device with the size between 1 cm and 2 cm.
Additionally, U.S. Pat. No. 8,432,619 disclosed an optical imaging lens constructed with an optical imaging lens having six lens elements. Although, the length of the optical imaging lens is reduced to 0.5 cm, which meets the demand of small sized product design, the image distortion of the optical imaging lens of patent '619 reaches 25%, and which means the image quality is too poor to meet specification requirements of consumer electronic products.
Therefore, there is needed to develop an optical imaging lens having six lens elements for high specification products.